CN100578117C - Method and air-conditioning system for realizing heating in winter by using water-cooled chiller - Google Patents

Abstract

The invention discloses a method and an air-conditioning system for realizing winter heat supply by using a water-cooled chiller unit. Under winter working conditions, the condenser of the water-cooled chiller unit is connected to a chilled water pump through a pipeline, so that the condenser of the water-cooled chiller unit is sequentially connected to the chilled water pump. , water separator, air-conditioning water system pipe network, and water collector form a heating water circulation loop; at the same time, the evaporator of the water-cooled chiller is connected to the cooling water pump through the pipeline, so that the evaporator of the water-cooled chiller is connected with the cooling water pump and the cooling tower in turn. A low-freezing-point solution circulation loop is formed between them; the low-freezing-point solution absorbs heat from the outdoor air in the cooling tower, and heats the heating water through the water-cooled chiller. The invention provides a new option for the winter heating system of large public buildings in cities, and can meet the needs of many public buildings for energy saving, money saving and emission reduction in winter heating.

Description

Method and air-conditioning system for realizing heating in winter by using water-cooled chiller

technical field

The invention belongs to the technical field of air conditioners, in particular to the technical field of cold and heat sources for air conditioners, and in particular to the technical field of air conditioners for water-cooled chillers.

Background technique

Water-cooled chillers are currently a common cold source for air-conditioning systems, but water-cooled chillers currently cannot operate in winter to provide indoor heat. Therefore, public buildings that use water-cooled chillers usually require heating such as boilers.

When gas and oil-fired boilers burn, they will emit a large amount of combustion products, generating various pollutants and greenhouse gases; and with the rise of international fuel prices, the operating costs of oil-fired gas boilers will also rise. Electric boilers are easy to control, but it is not energy-saving to directly convert high-grade electric energy into low-grade heat energy, and the operating cost is also high due to the large amount of electric energy required.

In China, there are quite a few public buildings that use water-cooled chillers and boilers as air-conditioning cold and heat sources. Therefore, if the water-cooled chiller can operate in the heat pump mode in winter, it can meet the heating needs of the building in winter while reducing building energy consumption and reducing pollutant emissions.

The technical key to solve the problem of water-cooled chillers to realize winter heating is to develop a suitable system structure, to develop a solution with low freezing point, high heat transfer efficiency, and low corrosion, and to make the operation of the system feasible and efficient.

Contents of the invention

The present invention aims to provide a method for realizing heating in winter by using a water-cooled chiller.

Another object of the present invention is to provide an air conditioning system that utilizes a water-cooled chiller to provide heat in winter.

A method of using a water-cooled chiller to realize winter heat supply is to connect the condenser 11 of the water-cooled chiller to the chilled water pump 31 through a pipeline in winter working conditions, so that the condenser of the water-cooled chiller is sequentially connected with the chilled water pump 31, water diversion A heating water circulation loop is formed between the device 32, the air-conditioning water system pipe network 34, and the water collector 35;

The water-cooled chiller evaporator 12 is connected to the cooling water pump 21 through a pipeline, so that the water-cooled chiller evaporator forms a low freezing point solution circulation loop with the cooling water pump 21 and the cooling tower 22 in turn;

The low-freezing solution absorbs heat from the outside air in the cooling tower and passes through the water-cooled chiller to heat the heating water.

The above method can realize the purpose of using the water-cooled chiller to supply heat in winter.

When heating in winter, what flows in the cooling tower and the cooling water pipeline is a low freezing point solution, the freezing point ranges from 0°C to -30°C, and the main components include: water, ethylene glycol, disodium hydrogen phosphate and dextrin; The mass content of alcohol is 5%-50%, the mass volume concentration of disodium hydrogen phosphate is 1-6g/L, and the mass volume concentration of dextrin is 0.2-5g/L. This kind of low freezing point solution has the characteristics of low freezing point, high heat exchange efficiency and low corrosion.

An air-conditioning system that utilizes a water-cooled chiller to provide heat in winter, including a water-cooled chiller 1, a chilled water pump 31, a water separator 32, an air-conditioning water system pipe network 34, a water collector 35, a cooling water pump 21, and a cooling tower 22;

The water-cooled chiller includes a water-cooled chiller condenser 11 and a water-cooled chiller evaporator 12;

In winter conditions, the condenser of the water-cooled chiller is connected to the chilled water pump through pipelines, so that the condenser 11 of the water-cooled chiller is in turn connected to the chilled water pump 31, the water separator 32, the air-conditioning water system pipe network 34, and the water collector 35. Form a heating water circuit;

The water-cooled chiller evaporator 12 can be connected to the cooling water pump 21 through a pipeline, so that the water-cooled chiller evaporator 12 forms a low freezing point solution circuit with the cooling water pump 21 and the cooling tower 22 in turn.

The low-freezing-point solution absorbs heat from the outdoor air in the cooling tower, and heats the heating water through the water-cooled chiller to increase the temperature of the heating water, which is used for heating in the pipe network of the air-conditioning water system.

This kind of air-conditioning system that uses water-cooled chillers to realize winter heating can not only be used in new buildings, but also a set of pipelines can be installed on the conventional water-cooled chiller air-conditioning system, so that it can cool in summer and also Heating can be realized in winter, specifically:

An air conditioning system that utilizes a water-cooled chiller to provide heat in winter, including a water-cooled chiller 1, a condenser 11 of the water-cooled chiller connected to a cooling water return pipe 52, a cooling water pump 21, a cooling tower 22, and a cooling water supply pipe 51 in order to form Cooling water circuit: the evaporator 12 of the water-cooled chiller unit is connected in sequence with the chilled water supply pipe 41, the chilled water pump 31, the water separator 32, the air conditioning water system pipe network 34, the water collector 35 and the chilled water return pipe 42 to form a chilled water loop ;

Connect the cooling water return pipe 52 and the chilled water supply pipe 41 with No. 1 bypass pipe 61 and No. 3 bypass pipe 63 respectively;

Connect the cooling water supply pipe 51 and the chilled water return pipe 42 with No. 2 bypass pipe 62 and No. 4 bypass pipe 64;

No. 1 bypass pipe, No. 2 bypass pipe, No. 3 bypass pipe and No. 4 bypass pipe are provided with No. 1 valve 71 , No. 2 valve 72 , No. 3 valve 73 and No. 4 valve 74 respectively.

The junction of the No. 1 bypass pipe 61 and the cooling water return pipe 52 is located downstream of the junction of the No. 3 bypass pipe 63 and the cooling water return pipe; and a No. 5 valve 75 is provided between the above two junctions;

The junction of the No. 3 bypass pipe 63 and the chilled water supply pipe 41 is located downstream of the junction of the No. 1 bypass pipe and the chilled water supply pipe, and a No. 6 valve 76 is provided between the two junctions.

The junction of the No. 2 bypass pipe 62 and the cooling water supply pipe 51 is located upstream of the junction of the No. 4 bypass pipe 64 and the cooling water supply pipe, and a No. 7 valve 77 is arranged between the two junctions;

The junction of the No. 2 bypass pipe 62 and the chilled water return pipe 42 is located downstream of the junction of the No. 4 bypass pipe 64 and the chilled water return pipe, and a No. 8 valve 78 is provided between the two junctions.

The invention changes the operation mode of the original water-cooled chiller through the pipeline, uses the configured low freezing point solution to absorb heat from the outdoor air in the cooling tower, and uses the water-cooled chiller to extract heat from the low freezing point solution and release it into the heating circulation water. to meet building heating needs. The system and operation mode of the water-cooled chiller set in winter heat pump working conditions proposed by the present invention use the solution with low freezing point, high heat exchange efficiency and low corrosion to propose a new winter heating and air conditioning system mode, which can provide heating for large public buildings in cities in winter The system offers new options. Through the implementation and promotion of this technology to meet the current demand for energy saving, money saving and emission reduction in winter heating of buildings.

Compared with systems using electric heating boilers for heating, the present invention can reduce heating operation costs by 50% to 70% under the condition of providing the same amount of heat. Compared with the heating system using gas and oil-fired boilers, the present invention can reduce the heating operation cost by 10% to 30% under the condition of providing the same amount of heat, calculated according to the current energy cost.

This technology can be applied not only in new buildings, but also in building energy-saving renovation. By modifying the existing air-conditioning system of chilled water-cooled units, the effect of cooling and heating can be realized at the same time. The application range is wide and the application effect is good. When applied to new buildings, it can reduce the initial investment cost of the project.

Description of drawings

Fig. 1 is a structural schematic diagram of an air-conditioning system that utilizes a water-cooled chiller to provide heat in winter in Embodiment 1

Fig. 2 is a cooling operation mode diagram of the air-conditioning system that uses water-cooled chillers to realize heating in winter in Embodiment 1

Fig. 3 is the heating operation mode diagram of the air-conditioning system that uses water-cooled chillers to realize winter heating in Embodiment 1

1-Water-cooled chiller, 11-Water-cooled chiller condenser, 12-Water-cooled chiller evaporator,

21-cooling water pump, 22-cooling tower,

31-chilled water pump, 32-water separator, 34-air conditioning water system pipe network, 35-water collector,

41-chilled water supply pipe, 42-chilled water return pipe, 51-cooling water supply pipe, 52-cooling water return pipe,

61-No. 1 bypass pipe, 62-No. 2 bypass pipe, 63-No. 3 bypass pipe, 64-No. 4 bypass pipe,

71-No. 1 valve, 72-No. 2 valve, 73-No. 3 valve, 74-No. 4 valve, 75-No. 5 valve,

76-No. 6 valve, 77-No. 7 valve, 78-No. 8 valve.

Detailed ways

Example 1

An air-conditioning system that utilizes a water-cooled chiller to provide heat in winter, as shown in Figure 1, includes a water-cooled chiller 1, the water-cooled chiller includes a water-cooled chiller condenser 11 and a water-cooled chiller evaporator 12; the water-cooled chiller condenser 11 It is sequentially connected with the cooling water return pipe 52, the cooling water pump 21, the cooling tower 22 and the cooling water supply pipe 51 to form a cooling water circuit; the water-cooled chiller evaporator 12 is connected with the chilled water supply pipe 41, the chilled water pump 31, the water distributor 32, The pipe network 34 of the air-conditioning water system, the water collector 35 and the chilled water return pipe 42 are connected in sequence to form a common path of chilled water;

Connect the cooling water return pipe 52 and the chilled water supply pipe 41 with No. 1 bypass pipe 61 and No. 3 bypass pipe 63 respectively;

Connect the cooling water supply pipe 51 and the chilled water return pipe 42 with No. 2 bypass pipe 62 and No. 4 bypass pipe 64;

No. 1 bypass pipe, No. 2 bypass pipe, No. 3 bypass pipe and No. 4 bypass pipe are provided with No. 1 valve 71 , No. 2 valve 72 , No. 3 valve 73 and No. 4 valve 74 respectively.

The junction of the No. 1 bypass pipe 61 and the cooling water return pipe 52 is located downstream of the junction of the No. 3 bypass pipe 63 and the cooling water return pipe; and a No. 5 valve 75 is provided between the above two junctions;

The junction of the No. 3 bypass pipe 63 and the chilled water supply pipe 41 is located downstream of the junction of the No. 1 bypass pipe 61 and the chilled water supply pipe, and a No. 6 valve 76 is provided between the two junctions.

The junction of the No. 2 bypass pipe 62 and the cooling water supply pipe 51 is located upstream of the junction of the No. 4 bypass pipe 64 and the cooling water supply pipe, and a No. 7 valve 77 is provided between the two junctions.

The junction of the No. 2 bypass pipe 62 and the chilled water return pipe 42 is located downstream of the junction of the No. 4 bypass pipe 64 and the chilled water return pipe, and a No. 8 valve 78 is provided between the two junctions.

The number of cooling water pumps can be one, or multiple cooling water pumps can be used in parallel. The number of chilled water pumps can also be one, or multiple can be used in parallel.

The water-cooled chiller can be a piston-type water-cooled chiller, a screw-type water-cooled chiller or a centrifugal water-cooled chiller, etc.

This air-conditioning system can realize cooling in summer and heating in winter.

The operation steps under the cooling condition in summer are as follows: as shown in Figure 2, close the No. 1 valve 71, the No. 2 valve 72, the No. 3 valve 73 and the No. 4 valve 74, open the No. Valve 77 and No. 8 valve 78. The chilled water return water enters the water collector 35 from the air-conditioning water system pipe network 34 in the building, and flows from the water collector through the chilled water return pipe 42 and No. 8 valve 78 into the water-cooled chiller evaporator 12 . After cooling down in the water-cooled chiller unit 1, the chilled water enters the chilled water pump 31 through the No. 6 valve 76 and the chilled water supply pipe 41, and is sent to the water separator 32 after being pressurized in the chilled water pump, and finally sent to the air-conditioning water system pipe in the building net34.

The cooling water enters the water-cooled chiller condenser 11 through the cooling water supply pipe 51 and the No. 7 valve 77 after heat exchange and cooling in the cooling tower 22 . After the temperature rises in the water-cooled chiller, it enters the cooling water pump 21 through the No. 5 valve 75 and the cooling water return pipe 52, and is sent to the cooling tower 22 by the cooling water pump.

Through the operation of the water-cooled chiller, the temperature of the cooling water rises and the temperature of the chilled water decreases; this working condition is the same as that of a common water-cooled chiller.

When cooling in summer, water is used as the medium flowing in the cooling tower and cooling water pipeline.

When heating in winter, what flows in the cooling tower and the cooling water pipe is a low freezing point solution, the freezing temperature of the low freezing point solution is 0～-30°C, and its main components include water, ethylene glycol, disodium hydrogen phosphate and dextrin; The mass percentage of ethylene glycol is 15%, the concentration of disodium hydrogen phosphate is 5g/L, and the concentration of dextrin is 2g/L.

The minimum evaporation temperature set by the water-cooled chiller is 0°C to -10°C.

In winter, the operation steps for using chillers to realize heating conditions are as follows: as shown in Figure 3, open No. 1 valve 71, No. 2 valve 72, No. 3 valve 73 and No. 4 valve 74, close No. Valve 76, No. 7 valve 77 and No. 8 valve 78. The heating water enters the water collector 35 from the pipe network 34 of the air-conditioning water system in the building, and flows from the water collector 35 through the chilled water return pipe 42, the No. 4 bypass pipe 64 and the cooling water supply pipe 51 into the water-cooled chiller condenser 11 . After the temperature rises in the water-cooled chiller 1, it enters the chilled water pump 31 through the cooling water return pipe 52, the No. Air-conditioning water system pipe network 34 in the building.

The low freezing point solution enters the water-cooled chiller evaporator 12 through the cooling water supply pipe 51 , the second bypass pipe 62 and the chilled water return pipe 42 after exchanging heat with the air in the cooling tower 22 . After cooling in the water-cooled chiller, the chilled water is sent to the cooling water pump 21 through the chilled water supply pipe 41, the No. 1 bypass pipe 61 and the cooling water return pipe, and then sent to the cooling tower after being pressurized by the cooling water pump.

The low-freezing-point solution absorbs heat from the outdoor air in the cooling tower, and heats the heating water through the water-cooled chiller to realize heat supply.

Example 2

The main components of the low freezing point solution are: water, ethylene glycol, disodium hydrogen phosphate, and dextrin; the mass percentage of ethylene glycol is 35%, the concentration of disodium hydrogen phosphate is 2g/L, and the concentration of dextrin is 5g/L. All the other are with embodiment 1.

Claims (4)

1. A method for using a water-cooled chiller to provide heat in winter, characterized in that: under winter conditions, the water-cooled chiller condenser (11) is connected to the chilled water pump (31) through a pipeline, so that the water-cooled chiller condenser (11) Form a heating water circulation loop with the chilled water pump (31), water separator (32), air-conditioning water system pipe network (34), and water collector (35) in turn; Connect to the cooling water pump (21) through a pipeline, so that the water-cooled chiller evaporator (12) forms a low freezing point solution circulation loop between the cooling water pump (21) and the cooling tower (22) in turn; The low-freezing-point solution absorbs heat from the outdoor air in the cooling tower (22), and heats the heating water through the water-cooled chiller (1). 2. A method for heating in winter by using a water-cooled chiller as claimed in claim 1, characterized in that the freezing point of the low freezing point solution ranges from 0°C to -30°C. 3. A method of using a water-cooled chiller to supply heat in winter according to claim 1 or 2, characterized in that the low freezing point solution includes water, ethylene glycol, disodium hydrogen phosphate and dextrin, ethylene glycol The mass content is 5%-50%, the mass volume concentration of disodium hydrogen phosphate is 1-6g/L, and the mass volume concentration of dextrin is 0.2-5g/L. 4. An air-conditioning system that utilizes a water-cooled chiller to provide heat in winter, including a water-cooled chiller (1), a chilled water pump (31), a water separator (32), an air-conditioning water system pipe network (34), and a water collector ( 35), cooling water pump (21) and cooling tower (22); The water-cooled chiller (1) comprises a water-cooled chiller condenser (11) and a water-cooled chiller evaporator (12); It is characterized in that the condenser (11) of the water-cooled chiller is connected to the chilled water pump (31) through a pipeline, so that the condenser (11) of the water-cooled chiller is sequentially connected with the chilled water pump (31), the water separator (32), the air conditioner A heating water loop is formed between the water system pipe network (34) and the water collector (35); the water-cooled chiller evaporator (12) is connected to the cooling water pump (21) through a pipeline, so that the water-cooled chiller evaporator (12) A low freezing point solution loop is formed between the cooling water pump (21) and the cooling tower (22).

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