JPS61173058A - Method of operating heat pump - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a method of operating a heat pump.

In a heat pump that has a cooling tower that also serves as a heating tower that collects heat from the air in the winter, antifreeze may be used as the circulating fluid to prevent the circulating fluid from freezing when used in the winter.

In this case, when the heating tower is also used as a cooling tower in the summer, there are two options: (a) collect the antifreeze and replace it with fresh water and use it as cooling water, or (b) use the antifreeze as is as cooling water. Two methods are possible. However, method a) requires a large tank for antifreeze recovery. Furthermore, in method (b), ``antifreeze, which has poor heat transfer, is used as cooling water, which increases the power of the heat pump and circulation pump,'' and ``because antifreeze is used all year round, there is less deterioration compared to when it is used only in winter.''"When used in the summer, the antifreeze becomes concentrated, so make-up water is required to dilute it. If the make-up water contains impurities, the antifreeze becomes contaminated, so it is necessary to replenish pure water, but There were drawbacks such as ``the equipment is expensive, SB, and maintenance costs are high.'' Therefore, the present invention aims to eliminate these drawbacks by improving the antifreeze recovery method (a). That is, at the beginning of the transition from winter operation to summer operation, the chilled water load is generally small and the outside temperature is low. If this period is used to concentrate the antifreeze solution and the concentrated antifreeze solution is collected in a tank, the tank can be made smaller and the drawbacks of the conventional method can be overcome.

The figure shows an example of a heat pump system that implements the method of the present invention.
, hot water condenser 2, booster compressor 6, cooling water condenser 4, main compressor 5. It has a brine (antifreeze) evaporator 6 and a cold water evaporator 7.

Brine (antifreeze) is circulated from the heating tower/cooling tower 1 (hereinafter simply referred to as tower 1) by a circulation pump 71, through piping 21 and 22, and through piping 2 and 24 to the cooling water condenser. Moving on to 4, piping 26
．． 27 to the siline evaporator 6. 25 is condenser 4
A heat exchange section 28 inside indicates a heat exchange section within the evaporator 6.

During the winter, the refrigerant flows from the si-line evaporator 6 to the pipe 66.
It goes to the main compressor 5, and the following piping 37. Cooling water condenser 4
, piping 68. Booster compressor 6, piping 39. Condenser 2 for hot water, piping 40, condenser 4, piping 41, evaporator 7 for cold water, piping 35. This becomes the evaporator 6. That statement 56, 57,
59, 61, 62 are opened, and valves 51, 52, 54,
55 and 60 are closed, and the antifreeze circulation path and tank 8 are disconnected.
) is done.

Note that 56 is a check valve, and 72 is a replenishment pump. The valve 58 is opened and closed depending on the pressure of the evaporator 7.

To explain the operation of the system in winter, the refrigerant is evaporated in the brine evaporator 6, takes heat from the brine (i.e., antifreeze) in the piping in the heat exchanger 28, goes to the compressor 5 in the piping 36, and is transferred to the cooling water in the piping 37. It is discharged to the condenser 4 for use. Next, the pipe 68 goes to the booster compressor 6, and the pipe 39 goes to the hot water condenser 2.
The heat exchange section 31 gives heat to hot water for heating and the like flowing through the piping 29.50, and the water is condensed. The cold water passes through the condenser 4 again through the pipe 40, goes to the cold water evaporator 7 through the pipe 41, is partially evaporated, and flows through the pipes 52 and 63, and then is transferred to the heat exchange section 3.
4 removes heat and returns to the evaporator 6 through a pipe 65.

Antifreeze as a brine is circulated by a circulation pump 71, but in winter, it is sprinkled with water from the water sprinkler section 11 in the tower 1 to collect heat from the outside air, and then enters the brine evaporator 6 via piping 21 and piping 27.26. Heat is applied to the refrigerant in the heat exchange section 28, and the refrigerant returns to the tower 1 through the piping 22. Note that 12 indicates a fan that blows outside air.

K starts summer operation from this state, in the example shown, piping 2
6. Open the valves 55 and 60 of the pipe 43 that passes through 27 to collect the antifreeze in the system into the tank 8.

Two methods have been proposed: injecting fresh water into the system or continuing to use antifreeze in the summer, but as mentioned above, both methods have many drawbacks.

For summer operation, open valves 51, 52, and 58, and close valve 54.
, 55, 56, 57.60 close. Then, the refrigerant evaporates in the cold water evaporator 7, removes heat from the cold water for air conditioning, etc. flowing through the pipes 52 and 38, goes to the main compressor 5 through the pipe 42, then enters the cold water condenser 4 through the pipe 37, and passes through the pipe 2L24. Cooling water (water or antifreeze as described above) flowing through the evaporator 7 gives K heat and returns to the evaporator 7 via a pipe 41. The cooling water is heated in the heat exchange section 25 in the condenser 4, returns to the tower 1 through the piping 22, radiates heat into the atmosphere by sprinkling water, and is transferred to the υ piping 2 by the pump 71.
1 into the pipe 26.

In the operating method of the present invention, during the transition from winter operation to summer operation, initially the chilled water load is generally small;
Take advantage of the period when the outside temperature is low and start summer operation by using antifreeze for a while.

Then, as the antifreeze fluid circulates within the system and radiates heat through water sprinkling within the tower 1, water evaporates and becomes concentrated little by little. In this way, when the concentration has progressed to a certain extent, the concentrated antifreeze solution can be collected in the tank 8, so that the tank can be made smaller. For example, if 30% ethylene glycol water is concentrated to 60% and collected in tank 8, the size of the cypress can be made 1A. By using fresh water after recovering the antifreeze from the system, all of the conventional drawbacks could be overcome.

In an actual device, a means for detecting the concentration of antifreeze liquid may be provided at an appropriate location in the system to issue a command to stop the concentration operation, or a means for detecting the liquid level in a cooling tower that also serves as a heating tower may be provided. After confirming that the antifreeze concentration has progressed to a predetermined level, a command to stop the concentration operation may be issued.

Also, during winter heat collection operation, antifreeze tends to be diluted, but at the end of winter heat collection operation, let the antifreeze be diluted and store the increased amount in the tank. ,
A method may be adopted in which the diluted antifreeze solution stored in this tank during the above-mentioned concentration operation period at the beginning of summer operation is also concentrated at the same time.

[Brief explanation of drawings]

The figure is a system diagram of a heat ponzo with a cooling tower that also serves as a heating tower, which implements the operating method of the present invention. Explanation of symbols 1... Cooling tower that also serves as a heating tower, 2
... Hot water condenser, 6... Two Star compressor, 4.
... Cooling water condenser, 5... Main compressor, 6... Siline evaporator, 7... Cooling water evaporator, 8... Tank, 7
1.72...Pump.

Claims (3)

[Claims] (1) In the operating method of a heat pump equipped with a cooling tower that also serves as a heating tower, which collects heat from the air using antifreeze in the winter, the antifreeze is used directly as cooling water during the initial transition to summer operation. The concentrated antifreeze is collected in a tank, and fresh water is injected into the system that was previously filled with antifreeze, so that the fresh water is used as cooling water during subsequent summer operations. How to operate a heat pump with a cooling tower that also serves as a heating tower. (2) In the above operating method, in order to confirm that the antifreeze concentration in the heating tower has progressed to a predetermined level and stop the concentration operation, the liquid level in the heating tower/cooling tower section is detected and an alarm is issued. The method of operating a heat pump according to claim 1, characterized in that the heat pump generates a heat pump. (3) A patent characterized in that in the above operating method, the concentration of antifreeze is detected and an alarm is issued in order to confirm that the concentration of antifreeze in the heating tower has progressed to a predetermined level and to stop the concentration operation. A method for operating a heat pump according to claim 1.